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In article .com,
"Wimpie" wrote: Hello Owen, You are right, feeding in the middle is good, your feed line is in the symmetry plane, where you have no E-field component parallel to your feed line. The line itself will not distort the radiation pattern. When it is a halve wave mono band antenna I would use a coaxial feeder with balun (current mode balun with ferrite cores for example). When the antenna has to work over multiple bands, you get problems with the impedance when your dipole is a full wave. Matching the coaxial feeder/balun combination will make almost sure all your power will be wasted in the form of heat in the balun and or the coaxial feeder. In that case I would prefer a symmetrical line (can have extremely low loss) and a symmetrical tuner. When one end of the dipole is close to ground or a large metal structure, you may feed the dipole at that end as an alternative. When your dipole is a multiple of halve a wavelength, the input impedance at the ends is in the high kOhm range. So you will have a relative low feed current and therefore also low ground current (so the ground can be relatively bad). I hope this and the other replies will help you to make good decision on what to do. Wim PA3DJS. yes thank you it will i appreciate everyones help it will allow me to narrow down my guesses and know a bit better what to expect for sure wish there was classes on this stuff i dunno experimenting around with antennas is a lot of fun ml |
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